The present invention relates to apparatus for treating amblyopia and similar eye conditions caused by a lack of acuity which is not of a refractive or transparent nature.
As is explained in the copending application, it has been found that amblyopia can be treated, with a significant increase in acuity, using apparatus which isolates the affected eye, presents a solitary visual target of minimum discernible size, and forces the subject to focus on and identify figures displayed on the target. The treatment is simple and easy, requiring merely five minutes, twice a day. In each case, examination of the subject's eyes demonstrates that the improvement in acuity is not a function of refractive or transparent changes in the subject's eye. This basic apparatus using a lighted target was employed both in a large darkened room, and contained in a darkened case using two mirrors and a lens to expand the optical distance within a contracted space.
Although this method and basic apparatus achieved remarkable results, the apparatus itself was deficient in a number of respects. The use of only a single solitary target required the target to be physically moved each time the acuity level had to be changed. With use of the unit contained in a case, this required opening the case, readjusting or changing the target and the lens to one of many predetermined locations, each location providing a particular acuity level, and then reassemblying the apparatus. This usually amounted to far too complicated a procedure to provide treatment at multiple acuity levels during a single treatment. Additionally, many people, particularly young children, have great difficulty correctly changing the lens and target locations. A further problem with the basic apparatus is that it did not make optimum use of space, thus creating a somewhat unwieldy package to transport, store, and use. Finally, the basic apparatus provided minimum feedback to the user, requiring the user to keep track of the number of correct and incorrect responses he had during a given session.
In light of the above considerations, it is a primary object of the present invention to provide improved apparatus for treatment of amblyopia and similar eye conditions which can be easily and rapidly switched between various levels of acuity demand.
It is a further object of the present invention to provide an acuity therapy unit which provides a full range of acuity demands within a compact and easily portable case.
It is an additional object of the present invention to provide an acuity therapy unit which tallies the responses of a user and provides a read-out of the number of correct responses given during a session.